could you explain me when should I use was+ verb+ing and had been + past participle?? I have school leaving exams in two days and I am still doing mistakes in exercise, where I have to fill in the correct tense. I was searching a lot where to use had been and past progressive, but I haven't found it.
Example of sentence, where I've made mistake... could you explain me what's the answer and why? : Mary went for a swim after work yesterday. She needed some exercise because she ..... (sit) in an office all day in front of computer.
My answer was: was sitting but the correct one is: had been sitting
Thank you for any answer before 2th April.
The past perfect progressive "had been sitting" indicates that the sitting began some time in the past, continued for a period of time and then stopped at some point in time before she went for a swim.
The ordinary past progressive "was sitting" would indicate that, at some point in the past, she was in her office, in front of the computer, when something else happened.
"She was sitting in front of her computer when the telephone rang."
It's possible that the caller asked her, "What are you doing?" and she replied, "I'm sitting in front of my computer". The action described by the simple past -- the telephone rang -- happened while she was sitting.
However, the swimming happened after the sitting. She sat, she stopped sitting, then she went for a swim.
"She was sitting in front of her computer when she went for a swim." That sentence is nonsense -- it would mean that she dived into the pool while still seated in front of her computer. Imagine her diving in together with her desk and computer. How many times have you ever seen that happen?
"She had been sitting in front of her computer when she went for a swim." That's better, because the past perfect progressive indicates that she was no longer in front of her computer when she went swimming.